Expandable graphite and method

Abstract

Intercalated graphite flake which has enhanced exfoliation volume characteristics at relatively low exfoliation temperatures e.g. 600° C. is made by heating a blend of intercalated particles and an organic reducing agent in the temperature range of 25° to 110° C.

What is claimed is: 
     
       1. Method for providing intercalated graphite flake with increased exfoliation volume at exfoliation temperatures as low as 600° C. which comprises: (i) treating of graphite flake with an oxidizing intercalant solution to provide intercalated graphite flake having a surface film of oxidizing intercalant solution; (ii) blending said intercalated graphite flake which has a surface coating film of the oxidizing intercalant solution with an organic agent reactive with the oxidizing intercalant solution at temperatures of from 25° C. to 110° C., selected from sugars, alcohols, aldehydes and esters in an amount of from 0.75 to 4% by weight of the graphite flake; and (iii) heating the blend of step (ii) to a temperature in the range of 25° C. to 110° C. to promote reaction of the organic agent with the coating of oxidizing intercalant solution. 
     
     
       2. Method in accordance with claim 1 wherein a temperature in the range of 25° C. to 110° C. is maintained for at least one-half hour. 
     
     
       3. Method in accordance with claim 1 wherein said oxidizing intercalant solution is a mixture of nitric acid and sulfluric acid. 
     
     
       4. Method in accordance with claim 1 wherein said organic agent is decanol. 
     
     
       5. Method in accordance with claim 1 wherein said organic agent is hexadecanol. 
     
     
       6. Method in accordance with claim 1 wherein said organic agent is 1-octanol. 
     
     
       7. Method in accordance with claim 1 wherein said organic agent is 1-propanol. 
     
     
       8. Method in accordance with claim 1 wherein said organic agent is 1,3 propanediol. 
     
     
       9. Method in accordance with claim 1 wherein said organic agent is 1, 10 decanediol. 
     
     
       10. Method in accordance with claim 1 wherein said organic agent is decylaldehyde. 
     
     
       11. Method in accordance with claim 1 wherein said organic agent is ethylene glycol. 
     
     
       12. Method in accordance with claim 1 wherein said organic agent is monostearate. 
     
     
       13. Method in accordance with claim 1 wherein said organic agent is sucrose.